Roller bearing having a forcible lubrication function

ABSTRACT

A roller bearing having a forcible lubrication function comprises an outer race provided with a radial rib directed inwardly. The bearing has a cage provided with a circular ring portion situated axially outwardly of the rib of the outer race to overlap the rib with a desired clearance to provide forced circulation of lubricant about the bearing.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to the lubrication of a bearing such as a needleroller bearing, a long cylindrical roller bearing or a cylindricalroller bearing which is provided with a cage.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide a roller bearinghaving a forcible lubrication function. The bearing has an outer racewith a rib and a cage provided at one or, perhaps, both ends with aradial circular ring portion(s) situated axially outwardly of the rib(s)of the outer race and radially overlapping said rib(s) with a suitableclearance(s) interposed dimensioned to allow the flow of oil, wherebylubricating oil in the bearing may be forcibly discharged outwardly bysaid circular ring portion while, at the same time, lubricating oilaround the bearing may be drawn into the bearing to thereby provide goodlubrication of the bearing, and the discharge of heat and dust or otherforeign material are carried out effectively.

The invention will become fully apparent from the following detaileddescription thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal cross-sectional view showing the essentialportions of a first embodiment of a bearing according to the presentinvention.

FIG. 2 is a longitudinal cross-sectional view showing the essentialportions of a second embodiment of a bearing according to the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will herein after be described with respect to tworepresentative embodiments shown in FIGS. 1 and 2. Reference numeral 1designates a shaft, reference numeral 2 denotes the outer race (whichmay be solid-shaped or shell-shaped) of a roller bearing which rotatablysupports the shaft 1, reference numeral 3 designates a roller (only oneof the rollers is shown), and reference numeral 4 denotes a cage. Theouter race 2 is formed with radially ribs 22, 22a directed inwardly atthe opposite ends of an inner track 21.

First, in a first embodiment shown in FIG. 1, the cage 4 is formed witha circular ring portion 42 situated axially outwardly of the outer raceand extending radially outwardly of the outer race. The ring portion 42extends from one end of a cylindrical portion 41 having windows forholding and guiding the respective rollers. The circular ring portion 42of the cage opposed to the rib 22 of the outer race has a suitable widthl over which the circular ring portion radially overlaps the rib 22, andis opposed to the rib 22 with a suitable clearance S1 interposed betweenthe circular ring portion and the outer side surface of the rib. Also,clearances S2 and S3 dimensioned so as not to restrain the rotation ofthe cage and to allow the flow of lubricating oil during the rotation ofthe bearing, are formed between the outer peripheral surface of saidcylindrical portion 41, which is the main body of the cage, and theinner peripheral surface of the rib 22 and between the inner peripheralsurface of the cylindrical portion 41 and the outer peripheral surfaceof the shaft 1, respectively.

FIG. 2 shows a second embodiment of the present invention. In thisembodiment, circular ring portions 42, 42a of the cage are formed at theopposite ends of the main body 41 and the respective relation of thecircular ring portions 42, 42a to the ribs 22, 22a is the same as thatin the first embodiment.

Particularly in this embodiment, with the machinability of the circularring portions 42, 42a and the assemblage thereof to the outer race beingtaken into account, circular ring portion 42a is formed by integrallycoupling a doughnut-shaped member formed separate from the cylindricalportion 41 of the cage to the cylindrical portion. This one circularring portion 42a need not always be formed by a separate member but bothof the circular ring portions may sometimes be formed unitarily with thecylindrical portion.

As described above, the roller bearing of the present invention is of aconstruction which has, at least one end of the cage, a circular ringportion extending radially outwardly and opposed to the outer sidesurface of the rib of the outer race with a desired clearance interposedtherebetween, and therefore, where the bearing is used in a casecontaining lubricating oil therein, the lubricating oil around thebearing is circulated and supplied to the bearing. That is, the circularring portions 42, 42a of the cage 4 acts as a slinger by the rotation ofthe cage 4 and, by the centrifugal force thereof, the lubricating oil isflung outwardly through the clearance S1 between the circular ringportions 42, 42a and the ribs 22, 22a of the outer race, and thelubricating oil within the bearing is drawn out through the clearance S2between the outer peripheral surface of the cylindrical portion 41 ofthe cage 4 and the inner peripheral surface of the rib 22 of the outerrace. Therefore, lubricating oil within the bearing is drawn into theinterior of the bearing through the clearance S3 between the innerperipheral surface of the cylindrical portion 41 of the cage and theouter peripheral surface of the shaft 1. By such action being performed,forcible lubrication of the interior and exterior of the bearing by thelubricating oil is effected.

Accordingly, it becomes possible that foreign material such as abrasionpowder within the bearing is discharged outwardly and fresh lubricatingoil is supplied to the interior of the bearing, and also heat generatedthe bearing is removed by to said circulation of the lubricating oil,thus prolonging the service life of the bearing.

Of course, the means for forming the circular ring portions of the cageis not restricted to the illustrated embodiments, but it may be suitablymodified in practice in accordance with the shape, material, thicknessand size of the cage. Particularly, where the cage is made of plastics,it can be injection-molded and thus various modifications or treatmentsmay be applied to the cage. For example, it becomes easier to provide,on the peripheral surface of the circular ring portion or the main bodyportion, a groove for ensuring more effective discharge and inflow ofthe lubricating oil. Also, the circular ring portion may be continuousor discontinuous circumferentially thereof.

I claim:
 1. A bearing assembly for a rotating element, including anouter race having a rib extending radially inwards from an end portionthereof, a plurality of rollers held within said race for rotationalmovement about the rotating element, a cage engaging said rollers formovement therewith, and means for forcibly circulating lubricant throughthe bearing assembly, said means including a first clearance formedbetween the outer surface of said cage and the inner surface of saidrace, a second clearance formed between the inner surface of said cageand the outer surface of the rotating element, and a ring portioncarried by said cage and extending axially outward from said rib with athird clearance therebetween, said clearances being sufficient to causelubricant to be extracted from the bearing assembly through said firstand third clearances by the centrifugal forces applied to the lubricantby the rotation of said rotating element and to be drawn into thebearing assembly through said second clearance.
 2. A bearing assemblyfor a rotating element, including an outer race having respective ribsextending radially inwards from each end portion thereof, a plurality ofrollers held within said race for rotational movement about the rotatingelement, a cage engaging said rollers for movement therewith, and meansfor forcibily circulating lubricant through the bearing assembly, saidmeans including first clearances formed between the outer surface ofsaid cage and the inner surface of said race, second clearances formedbetween the inner surface of said cage and the outer surface of therotating element, and a respective ring portion carried at each end ofsaid cage and extending axially outward from a respective rib with thirdclearances therebetween, said clearances being sufficient to causelubricant to be extracted from the bearing assembly through said firstand third clearances by the centrifugal forces applied to the lubricantby the rotation of said rotating element and to be drawn into thebearing assembly through said second clearances.